Cowling assembly for outboard motor

ABSTRACT

A cowling assembly for covering an internal combustion engine of an outboard motor includes a bottom cowling, with a bottom-side hook, attached to an opening edge of the bottom cowling. The cowling assembly further includes a top cowling, and a top-side hook, attached to an opening edge of the top cowling is engageable with the bottom-side hook. A mounting boss is additionally secured to an inner side of the opening edge of the top cowling, and the top-side hook is attached to the mounting boss.

PRIORITY INFORMATION

The present application is based on and claims priority under 35 U.S.C.§ 119 to Japanese Patent Application No. 2004-024892, filed on Jan. 30,2004, the entire contents of which are expressly incorporated byreference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cowling assembly for an outboardmotor having top and bottom cowling members for covering an internalcombustion engine.

2. Description of the Related Art

Conventionally, outboard motors include internal combustion enginescovered with top and bottom cowlings. The top and bottom cowlings oftenattach to one another by engaging bottom-side hooks attached to theopening edge of the bottom cowling and top-side hooks attached to theopening edge of the top cowling. For example, Japanese patentJP2002349257A2, entitled OUTBOARD MOTOR, discloses such an arrangement.

SUMMARY OF THE INVENTION

An aspect of at least one invention described herein includes therealization that when hook mounting bosses for securing the top-sidehooks are formed integrally with the top cowling by molding, the topcowling can be excessively thick in the area of the molding. The topcowling is thus heavier, especially when the top cowling is made of areinforced resin, as is frequently the case. To address such a need, anaspect of at least one invention described herein involves providing acowling assembly with a top cowling formed of lighter weight materialsuch that the top cowling is strong enough to support hook mountingbosses for securing the top-side hooks and further is strong enougharound an opening edge of the top cowling to suitably engage and sealwith the bottom cowling.

Another aspect of at least one invention described herein includes therealization that although mounting bosses for securing top-side hookscan be formed separately from the top cowling and can then be attachedto the top cowling, the joints of such separately formed bosses areusually at least partially exposed to the outside of the top cowling,which adversely affects the appearance of the outboard motor.

Thus, in accordance with an embodiment, a cowling assembly for anoutboard motor, comprising a top cowling and a bottom cowling forcovering an internal combustion engine of the outboard motor isprovided. The cowling assembly comprises a bottom-side hook attached toan opening edge of the bottom cowling. A top-side hook is attached to anopening edge of the top cowling and engageable with the bottom-sidehook. Additionally, a mounting boss is secured to an inner side of theopening edge of the top cowling, wherein the top-side hook is attachedto the mounting boss.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention are described below with reference to the drawings ofpreferred embodiments, which embodiments are intended to illustrate andnot to limit the present invention.

FIG. 1 is a side view of one embodiment of an outboard motor, having topand bottom cowling members and with certain internal componentsillustrated in phantom line.

FIG. 2 is a top plan view of the outboard motor of FIG. 1 with a topcowling member removed and an engine illustrated in phantom line.

FIG. 3 is a side elevational and partial cut-away view of the topcowling member of FIG. 1 removed from the outboard motor, andillustrating a top-side attaching part of the top cowling member.

FIG. 4 is a bottom plan view of the top cowling member removed from theoutboard motor.

FIG. 5 is an enlarged top plan view of a bottom-side attaching partconnected to the bottom cowling member.

FIG. 6 is a cross-sectional view of FIG. 5 taken along the VI-VI line.

FIG. 7 is a cross-sectional view of FIG. 5 taken along the VI-VII line.

FIG. 8 is an elevational view of a top-side hook attached to the topcowling.

FIG. 9 is a partial sectional view illustrating the attached state ofthe top cowling and an annular rail according to an embodiment.

FIG. 10 is another partial sectional view illustrating the attachedstate of the top cowling and the bottom cowling.

FIG. 11 is partial sectional view of a seal formed between the topcowling and the bottom cowling according to an embodiment of at leastone invention described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-11 illustrate a cowling assembly 7 for an outboard motor 1configured in accordance with certain features, aspects, and advantagesof at least one invention described herein. The outboard motor 1 merelyexemplifies one type of outboard drive. However, the various cowlingassemblies disclosed herein can be used with other types of devices thatbenefit from cowling types of enclosures. Such applications will beapparent to those of ordinary skill in the art in view of thedescription herein. These inventions are not limited to the embodimentsdescribed, which include the preferred embodiments, and the terminologyused herein is not intended to limit the scope of the presentinventions.

The general structure of an outboard motor is described with referenceto FIG. 1. As depicted in FIG. 1, an outboard motor 1 is attached to astem plate 100 a of a hull 100 of a boat or other watercraft by a clampbracket 2. A swivel bracket 5, having upper and lower damper members 3for elastically supporting a propulsion unit 4, is supported forvertical rotation by a cramp bracket 2 via a tilt shaft 6.

The propulsion unit 4 has a housing comprising a cowling assembly 7, anupper case 8, and a lower case 9. An internal combustion engine 10, suchas, for example, a four-cycle internal combustion engine, can be housedin the cowling assembly 7. However, other engines can also be used. Invarious embodiments, the upper case 8 is attached to a lower part of anexhaust guide plate 11. The internal combustion engine 10 can besupported on the exhaust guide 11 plate.

As depicted in FIG. 1, the internal combustion engine 10 has acrankshaft 12 extending vertically and connected to an upper end of adrive shaft 13, which extends vertically through the upper case 8. Alower end of the drive shaft 13 is connected to a forward/reverseswitching mechanism 14 housed in the lower case 9. A propeller shaft 15extends horizontally from the forward/reverse switching mechanism 14 andhas a rear end, which protrudes outside of the lower case 9, and towhich a propeller 16 is attached.

The cowling assembly 7 can comprise a bottom cowling member 20 and a topcowling member 40 that, in various embodiments, attach to one another,described in greater detail below with reference to FIGS. 2 to FIG. 10.

FIG. 2 is a plan view of one embodiment of the bottom cowling 20, withthe internal combustion engine 10 illustrated in phantom line. Thebottom cowling 20 can be made of an aluminum material by die-casting, orany other method.

The bottom cowling 20 has an opening edge 20 a, from which a rib 20 a 1extends upwards, also shown in another perspective in FIG. 7. The rib 20a 1 can be configured to form a seal between the bottom cowling 20 andthe top cowling 40, also described below with reference to FIG. 10.

Bottom-side attachment assemblies 21 can be provided at a plurality ofpositions along the opening edge 20 a of the bottom cowling 20. Forexample, in the embodiment depicted in FIG. 2, bottom-side attachmentassemblies 21 are provided at three positions along the opening edge 20a of the bottom cowling 20, namely, at a position that faces the hull100 and at positions on the port and starboard sides of the bottomcowling 20.

FIG. 5 is a plan view of one embodiment of a bottom-side attaching part,and FIGS. 6 and 7 are cross-sectional views of FIG. 5, taken along thelines VI-VI and VII-VII, respectively. Each of the bottom-sideattachment assemblies 21 comprises a supporting holder 22, a bottom-sidehook 23, a mounting bolt 24, a spring 25, and a lever 26. The supportingholder 22 is secured to a mounting boss 20 b extending inward from theopening edge 20 a of the bottom cowling 20 by mounting bolts 27. Thebottom-side hook 23 is attached, by the mounting bolt 24, to asupporting shaft 28 rotatably supported by the supporting holder 22. Astay 29 is attached to the mounting boss 20 b by a mounting bolt 30, andthe spring 25 is provided between the stay 29 and a supporting part 23 aof the bottom-side hook 23. The spring 25 is urged in a direction toraise an engaging part 23 b of the bottom-side hook 23 that is attachedto the opening edge 20 a of the bottom cowling 20. The supporting holder22 has a positioning recess 22 a. As depicted in FIG. 7, the bottomcowling 20 further comprises a seal member 50, which includes anengaging part 50 a and a seal part 50 b, and whose function will bedescribed in greater detail with respect to the attachment of the topcowling 40 and the bottom cowling 20.

FIGS. 3 and 4 provide two views of an embodiment of a top cowling 40.FIG. 3 is a side view of the top cowling member 40, from which anexterior part is cut away to reveal a top-side attachment assembly 43inside the top cowling member 40. The top-side attachment assembly 43 isdescribed in greater detail below.

FIG. 4 is bottom plan view of one embodiment of the top cowling 40. Thetop cowling 40 can be provided with a baffle plate 41 covering an intakeopening 42 of the top cowling 40. The baffle plate 41 can include a pairof right and left air intake openings 41 a. Air introduced through theintake opening 42 and sucked through the air intake openings 41 a can beused to cool the engine 10. The air can also be sucked through an aircleaner (not shown) and then into the engine 10 for combustion therein.Water drops separated by the baffle plate 41 are collected into adischarge hose 49 and can be discharged so as not to fall onto theengine 10.

In various embodiments, the top cowling 40 is made by pressing anonferrous material into a desired shape. For example, the top cowling40 can be formed by pressing a plate of a nonferrous metal, such asaluminum or magnesium. When the top cowling is formed by pressing anonferrous material, the top cowling can be thin as compared with onesproduced by the methods using other metal. Also, the top cowling can berecyclable and can largely contribute to the weight reduction of theoutboard motor. Furthermore, since the top cowling can be formed withoutburring and buff finishing used for casting products, the appearancequality can be improved and the number of steps in the productionprocess can be reduced.

As further depicted in FIGS. 3 and 4, the top cowling 40 has an openingedge 40 a. The opening edge 40 a of the top cowling 40 has an inner side40 a 1.

With reference to FIGS. 8-10, each of the top-side attaching parts 43comprises a mounting boss 44, a top-side hook 45, and a mounting bolt46. In various embodiments, the mounting bosses 44 are secured by one ormore of a variety of methods. For example, the mounting bosses 44 can besecured with an adhesive, which allows the mounting bosses 44 to besecured easily and firmly. The mounting bosses 44 can also be secured bywelding or by another method.

An annular rail 80 is attached to the mounting bosses 44 by mountingbolts. In a preferred embodiment, the annular rail 80 is formed bycurving an elongated metal strip into a shape which fits the innerperiphery of the opening edge 40 a. For example, the annular rail 80 canbe formed by stamping a large metal plate material into a shape whichfits the inner periphery of the opening edge 40 a. However, othermanufacturing techniques can also be used.

As depicted in FIGS. 9 and 11, a ridge 80 a is formed on one of theupper and lower sides of the annular rail 80 to increase the strength ofthe annular rail 80. In the embodiments depicted in FIGS. 9 and 11, theridge 80 a is formed the upper side of the annular rail 80. The ridge 80a can alternatively be formed on the lower side of the annular rail 80,or the annular rail 80 can have ridges on both sides. The annular rail80 can be formed of a flat plate or formed by laminating a plurality ofplates. In some embodiments, a metal, such as iron or SUS, is used asthe material for forming the annular rail 80. In other embodiments, theannular rail 80 can be made from aluminum or another material.

As further shown in FIGS. 9 and 11, an attaching surface 80 b of theannular rail 80 can be secured to the inner side 40 a 1 of the openingedge 40 a of the top cowling 40 with an adhesive. Additionally, mountingbosses 44 formed on the annular rail 80 can be used to secure theannular rail 80 to the top cowling 40. More specifically, attachingsurfaces 441 of the mounting bosses 44 can be secured to the inner side40 a 1 of the opening edge 40 a of the top cowling 40 with an adhesive.Thus, the annular rail 80 can be attached to the top cowling 40 easilyand firmly.

Advantages of securing the attaching surfaces 80 b and 441 of theannular rail 80 to the inner side 40 a 1 of the opening edge 40 a of thetop cowling 40 include the resulting reinforcement of the opening edge40 a and the enhanced mounting strength of the top cowling 40.

In various embodiments, top-side attachment assemblies 43 are providedat a plurality of positions around the top cowling 40. In a preferredembodiment, depicted in FIG. 4, top-side attachment assemblies 43 areprovided at three positions, namely, on a side of the top cowling 40that faces the hull 100 and positions on two opposing sides of the topcowling 40.

The top-side hooks 45 are secured to the mounting bosses 44 by themounting bolts 46. Since the top-side hooks 45 are attached to themounting bosses 44, which in turn are secured to the inside of the topcowling 40, components of the top-side attaching parts 43 are notexposed to the outside of the top cowling 40 and thus are protected frommoisture, and the quality of appearance of the outboard motor is thusenhanced. Furthermore, the mounting bosses thus serve as reinforcementand improve the mounting strength of the top cowling. Also, the improvedstructure can contribute to the weight reduction of the outboard motor.

Each of the mounting bosses 44 has a positioning damper 47. A leg member81 is attached to each of the mounting bosses 44 such that it extendsbeyond the opening edge 40 a of the top cowling 40. The leg members 81can be attached easily and firmly using the mounting bosses 44.

Referring now to FIG. 10, the top cowling 40 and the bottom cowling 20are shown in a state of attachment to one another. According to apreferred embodiment, to close the top cowling 40, engaging parts 45 aof the top-side hooks 45 are pressed against the engaging parts 23 b ofthe bottom-side hooks 23, thereby rotating the bottom-side hooks 23against the springs 25. After the engaging parts 45 a of the top-sidehooks 45 have passed, the engaging parts 23 b of the bottom-side hooks23 are rotated by the springs 25 in the opposite direction to theoriginal positions with the engaging parts 45 a of the top-side hooks 45below them, and the attached state shown in FIG. 10 is established.

As further depicted in FIG. 10, each of the mounting bosses 44 has apositioning damper 47. When the top cowling 40 and the bottom cowling 20are attached to each other, the positioning dampers 47 of the top-sideattaching parts 43 are engaged with the positioning recesses 22 a of thebottom-side attaching parts 21 to position the top cowling 40 and thebottom cowling 20 in a vertical direction.

When the top cowling 40 and the bottom cowling 20 are attached to oneanother, the seal member 50 provides a seal between the top cowling 40and the bottom cowling 20 as shown in FIG. 11. The seal member 50comprises an engaging part 50 aand a seal part 50 b. The seal member 50can be attached to the bottom cowling 20 by engaging the engaging part50 a with the annular rib 20 a 1 along the opening edge 20 a of thebottom cowling 20, while the seal part 50 b of the seal member 50extends all along the opening edge 20 a.

When the top cowling 40 and the bottom cowling 20 are attached to oneanother, the seal part 50 b is compressed between a lower side of theannular rail 80 and the inner side 40 a 1 of the opening edge 40 a toprovide a seal. In this embodiment, since a seal is formed by sealingsurfaces extending in different directions, namely the annular rib 20 a1 formed along the opening edge 20 a of the bottom cowling 20, the innerside 40 a 1 of the opening edge 40 a, and the annular rail 80 of the topcowling 40, a strong and effective seal can be formed.

Although this invention has been disclosed in the context of certainpreferred embodiments, it will be understood by those skilled in the artthat the present invention extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses of theinvention and obvious modifications and equivalents thereof. It is alsocontemplated that various combinations or sub-combinations of thespecific features and aspects of the embodiments can be made and stillfall within the scope of the invention. It should be understood thatvarious features and aspects of the disclosed embodiments can becombined with or substituted for one another in order to form varyingmodes of the disclosed invention. Thus, it is intended that the scope ofthe present invention herein disclosed should not be limited by theparticular disclosed embodiments described above, but should bedetermined only by a fair reading of the claims that follow.

1. A cowling assembly for an outboard motor, comprising a top cowlingand a bottom cowling for covering an internal combustion engine of theoutboard motor, said cowling assembly comprising: a bottom-side hookattached to an opening edge of the bottom cowling; a top-side hookattached to an opening edge of the top cowling and engageable with thebottom-side hook; and a mounting boss secured to an inner side of theopening edge of the top cowling, wherein the top-side hook is attachedto the mounting boss.
 2. The cowling assembly for an outboard motor ofclaim 1, wherein the mounting boss is secured to the inner side of theopening edge of the top cowling with an adhesive.
 3. The cowlingassembly for an outboard motor of claim 1, wherein a leg memberextending beyond the opening edge of the top cowling is attached to themounting boss.
 4. The cowling assembly for an outboard motor of claim 2,wherein a leg member extending beyond the opening edge of the topcowling is attached to the mounting boss.
 5. The cowling assembly for anoutboard motor of claim 1, wherein a positioning damper is attached tothe mounting boss.
 6. The cowling assembly for an outboard motor ofclaim 2, wherein a positioning damper is attached to the mounting boss.7. The cowling assembly for an outboard motor of claim 3, wherein apositioning damper is attached to the mounting boss.
 8. The cowlingassembly for an outboard motor of claim 1, wherein the top cowling isformed by pressing a nonferrous material.
 9. The cowling assembly for anoutboard motor of claim 3, wherein the top cowling is formed by pressinga nonferrous material.
 10. The cowling assembly for an outboard motor ofclaim 5, wherein the top cowling is formed by pressing a nonferrousmaterial.